National government initiatives have the potential to achieve population-wide reduction in salt intake
In almost all countries worldwide, most people eat too much salt. This can cause high blood pressure, which can lead to health problems, such as heart disease and stroke. To reduce the amount of salt eaten, governments in many countries have developed national salt reduction initiatives. These initiatives may be individually oriented, such as providing education about salt, or structurally oriented, to improve or offset the deficiencies which prevent people from obtaining food with lower salt. As the number of population-based initiatives to reduce salt rise worldwide, it is important for policy-makers to identify which population-level intervention are impactful and cost-effective.
A team of Cochrane authors based in Australia and Canada worked with Cochrane Public Health to examine whether national salt reduction initiatives have been effective in reducing the amount of salt consumed in those populations. Fifteen national initiatives including more than 260,0000 people were included, with 10 initiatives providing sufficient date for quantitative analysis. These were mostly conducted in high-income countries. The quality of the data was rated to be very low given the nature of the interventions does not lend to using controlled study design.
Population-level interventions in government jurisdictions for dietary sodium reduction have the potential to result in population-wide reductions in salt intake from pre-intervention to post-intervention, particularly if they have more than one intervention activity and incorporate interventions of a structural nature (e.g. large-scale efforts to lower the salt content of food products at the time of production), and particularly amongst men. Implementation of future initiatives should embed more effective means of evaluation to help us better understand the variation in the effects.
This Cochrane Review excluded a larger number of national salt reduction strategies because the data lacked pre and/or post data points which are needed to examine the impact of the intervention. There were 15 included initiatives in the review but with a wide variation in the elements they included, as well as the quality of evidence in their evaluation. For these reasons, it is difficult to interpret the current evidence and warrants more research. This review provides some evidence that national sodium reduction initiatives that are multi-component and include activities of a structural nature, such as policies to lower the salt levels in food in specific settings, appear to be more effective than single-component initiatives, such as information campaigns.
